Most scientists of the time believed the brain was a continuous, interconnected network. Cajal argued that the brain was composed of individual cells: neurons. In the 1950’s, high-resolution electron microscopes proved him right.

Why would someone like me, an illustrator, be interested in Señor Cajal?

Because he was also a wonderful artist (he studied art before attending medical school).

I write these posts to demonstrate the power and appeal of illustration to prospective clients– how does Cajal’s work fit into that?

Because it makes this very important point:

Working freehand, Cajal summarized what he saw under the microscope rather than making an exact copy. In a single sketch, he combined observations he made at different times, using different methods. He did this to illustrate a larger hypothesis, rather than just copying what he saw.

In other words, he did what every good illustrator tries to do: to render a fuller reality or “truth”– one that a photograph can’t fully capture.

Here’s an electron microscopy of the retina next to Cajal’s sketch. The photo is colorful, precise, literal, passive.